The 49, XXXXY Klinefelter variant is distinctive; classic findings include mental retardation, hyp ogonadism and radioulnar synostosis. Its incidence is estimated to be 1/80,000 to 1/100,000 male births. We report a case of 49, XXXXY syndrome confirmed by chromosomal study in neonatal period, whose clinical features included a coarse face, short neck, micropenis, and other multiple minor anomalies including simian creases. Echocardiography showed patent ductus arteriosus (PDA), and pulmonary hypertension. A multicystic kidney was found by abdominal ultrasonography.